Syntheses and structures of two coordination polymers formed by Ni(cyclam)(2+) cations and sulfate anions.

The asymmetric units of catena-poly[[(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ(4) N (1),N (4),N (8),N (11))nickel(II)]-μ(2)-sulfato-κ(2) O (3):O (4)], [Ni(SO(4))(C(10)H(24)N(4))] (n) (I), and catena-poly[[(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ(4) N (1),N (4),N (8),N (11))nickel(II)]-μ(2)-sul-fato-κ(2) O (3):O (4)] hemi[4,4',4'',4'''-(2,2',4,4',6,6'-hexa-methyl-[1,1'-biphen-yl]-3,3',5,5'-tetra-yl)tetra-benzoic acid] nona-hydrate], {[Ni(SO(4))(C(10)H(24)N(4))](2)·C(46)H(38)O(8)·18H(2)O} (n) (II), consist of two crystallographically unique centrosymmetric macrocyclic dications and a sulfate dianion. In II it includes additionally a mol-ecule of the undissociated acid (2,2',4,4',6,6'-hexa-meth-yl[1,1'-biphen-yl]-3,3',5,5'-tetra-yl)tetra-(benzoic acid) located on a crystallographic twofold axis and nine highly disordered water mol-ecules of crystallization. In both compounds, the metal ions are coordinated in the equatorial plane by the four secondary N atoms of the macrocyclic ligand, which adopts the most energetic-ally stable trans-III conformation. Two O atoms of the sulfate anions occupy the trans-axial positions resulting in a slightly tetra-gonally distorted trans-NiN(4)O(2) octa-hedral coordination geometry. The crystals of both compounds are composed of parallel coordination polymeric chains running along the [101] and [100] directions in I and II, respectively. The distances between the neighboring metal ions in the chains are significantly different [6.5121†(6)†à in I and 6.0649†(3)†à in II] and this peculiarity is explained by the different spatial directivity of the Ni-O coordination bonds (different S-O-Ni angles). As a result of the C-H⋯O hydrogen bonds between the methyl-ene groups of the macrocyclic ligands and the non-coordinated O atoms of the sulfate anion, the coordination-polymeric chains in I are arranged in the two-dimensional layers oriented parallel to the (010) and (101) planes, the inter-section of which provides the three-dimensional coherence of the crystals. The three-dimensional supra-molecular structure of the crystals II is determined by the network of strong hydrogen bonds formed by the carb-oxy-lic acid and the non-coordinated O atoms of the sulfate anions.